Shrinkage control of textiles



Patented Apr. 5, 1949 2,466,457 SHRINKAGE CONTROL OF TEXTILES John Edward Lynn, Old Greenwich, and Linton A. Fluck, Jr., Norwalk Conn., assignors to American Cyanamid Company, New York, N. Y., a corporation of Maine No Drawing. Application March 9, 1945, Serial No. 581,954

1 Claims. (01. 117-141) This invention relates to textiles and textileforming materials which are made resistant to shrinkage upon wetting or washing by the incorporation of resinous materials therein. While the invention is directed particularly to improved textile treating processes resulting in shrinkage resistance and in many cases improved tensile strength in the textiles and textile-forming materials it includes also the finished textiles themselves when prepared by the process of the invention.

It has recently been shown that textile materials, which term includes spun, woven, knitted and felted textiles as well as the raw materials such as loose wool, staple cotton fibers, etc., from which they are prepared, can be rendered resistant to felting and shrinking by impregnation with an aqueous dispersion of substantially unpolymerized alkylated melamine-formaldehyde condensation products, which are also known as alkylated methylol melamines. The impregnation of cellulosic textile materials with such solutions is,

described in U. S. Patent No. 2,339,203 dated January 11, 1944, whereas the treatment of woolen textile materials to reduce their felting and shrinking tendencies is described in U. S. Reissue Patent No. 22,566. The present invention constitutes an improvement in the processes and textile materials described and claimed in these patents.

We have found that substantial improvements are obtained when urea, thiourea or mixtures of urea and thiourea are applied 'to textile materials in conjunction with the application of aqueous dispersions of uncured alkylated melamine-formaldehyde condensation products. We have also found that similar advantages are obtained by applying melamine, guanidine, ammonia or other compounds capable of combining with formaldehyde such as, for example, phenols, cresols and the like in conjunction with the alkylated methyl- 0] melamines. Our invention in its broader aspects therefore includes textile treating procfises of the class described in which any suitable aterial capable of combining with formaldehyde 5 i incorporated into the textiles along with alkylated methylol melamines, but thiourea, urea and mixtures thereof constitute the preferred materials.

There is a considerable variation in the loss of 50 tensile strength in different textiles and textileforming materials as a result of their impregnation with alkylated methylol melamine solutions followed by curing the resin at elevated temperatures. reduced only relatively slightly'by this treatment, if at all. Cotton and rayon, on the contrary, suffer a considerable loss in strength. We have discovered, however, that formaldehyde-binding The tensile strength of woolen fabrics is particularly urea and thiourea, will prevent a large proportion of the loss in strength of cotton and rayon when treated with methylated methylol melamine or other alkylated melamine-formaldehyde condensation product solutions, and in the case of woolen textiles the tensile strength is actually increased. Moreover, the quantities of urea, thiourea and other formaldehyde-binding materials effective to accomplish these results are such that no serious reduction in shrinkage control is encountered, and therefore the process of our invention combines a high degree of shrinkage control with satisfactory strength in the treated textile material.

The preparation of water-soluble or water-dispersible alkylated methylol melamines and their application to textile materials is described in the patents referred to above, and need not be elaborated in detail. Although any alkylated methylol melamine may be employed, thev preferred materials are the water-soluble methylated methylol melamines containing about 2-6 molecules of combined methanol for each molecule of melamine. These products are prepared by condensing 2-6 mols of formaldehyde with 1 mol of melamine under slightly alkaline conditions, then acidifying to a pH of about 6.4, adding methyl alcohol and reacting with azeotropic distillation of a methanol-water mixture until the alkylation is completed. Other alkylated methylol melamines are prepared by a similar process, substituting ethanol, propanol, butanol and the like for the methyl alcohol. These resinous condensation products are preferably used in quantities of about 2-15%, based on the dry weight of the textile materials, although higher quantities up to 25% may be employed if desired.

The quantity of urea, thiourea or other aldehyde-binding material will vary with the nature of the textile materials. Thus, for example, rayon and cotton require more than wool. The amount may also vary with the type and quantity of alkylated methylol melamines employed. We have found that as little as 1% of urea or thiourea is effective to prevent substantial loss of strength in some cases, but the preferred quantities range from about 2 to about 10%. Ammonia is preferably used in considerably smaller quantities because of its lower molecular weight, while larger quantities of melamines, guanidines, phenols and thelike are employed for the same reason. It should be understood, however, that the invention in its broader aspects is not limited to these preferred quantities; for example, amounts of urea or thiourea up to 15-20% of the dry weight of the textiles may be employed in exceptional cases, as with some types of rayon, and are included within the broad scope of the invention. 7

materials such as those enumerated above, and The formaldehyde-binding materials, and parassess-r tlcularly urea and thiourea, are preferably incorporated into the aqueous solution of alkylsted,

methylol melamine prior to the impregnation of the textiles therewith. Similar results are obtainable however by using a two bath process in which the textiles are first impregnated with the resin solution and then with the aldehyde-binding agent, or the urea, thiourea or other aldehydebinding material may be impregnated into the textile materials before they are treated with the The invention will be further illustrated by I the following specified examples, which describe the finishing of representative textile fabrics; It should be understood, however, thatthe invention in its broader aspects is not limited to the specific materials shown in these examples; on the contrary, other textiles may be treated in similar manner and other alkylated methylol melamines and formaldehyde-binding agents may be employed.

EXAMPLE 1 All wool flannel cloth was treated for shrinkage control by impregnation with aqueous solutions of methylated methylol melamine containing 0.4% of diammonium hydrogen phosphate, based on the weight of the resin, followed by drying and curing by heating 9 minutes at 290 F.

Varying quantities of urea and thiourea. were dissolved in the aqueous resin solution prior to impregnation of the cloth therewith. The finished cloth was tested for tensile strength and for shrinkage control by standard methods. Tensile strength was measured on a Scott Tester, I. P. No. 3, with grab hooks set 3 inches apart. Shrinkage was determined by successive 10 minute launderings in a soap solution giving good running suds at 100 F., rinsing in warm water and drying fiat in an oven without tension after each wash.

The dried samples were conditioned over nightbefore measuring. A final one-hour laundering followed five such 10 minute treatments.

The following table gives the results obtained by this procedure with varying quantities of urea, thiourea. and methylated methylol melamine. In most cases several runs were made under the same conditions and with the same quantities of materials and the figures were averaged to reduce the limit of error of the method. Pieces of the same wool cloth were used throughout.

' 4 This example shows that optimum results are obtained onwoolbyusingabout3-6% ofureaor thiourea. Similar results are obtainable with mixturesof urea and thiourea.

nxamnz Nylon screen cloth having a tensile strength in pounds of 142.5 x 169.3, was impregnated by the procedure described in Example 1 with 2.5% of methylated methylol melamine containing 0.3%

of its weight of curing accelerator together with 4.8% of a stiffening composition. The stiffening composition was an equeous emulsion containing by weight of a solution in butanol of a soya fatty acid modified phthalic glyceride resin and 13.5% of a 50% butanol solution of a butylated urea-formaldehyde resin. The resin solids applied from this emulsion were therefore about 2%, based on the dry weight of the nylon. The

tensile strength of the treated cloth in pounds 7 was x 126.3.

Urea in amounts of 3% and 5%, based on the dry weight of the nylon, was added to samples of the treating composition. The tensile strength figures for the treated cloth were raised to 141.7 x and 154.7 x 179.7, respectively.

EXAMPLE3 Mercerized cotton twill was finished with 10% of methylated methylol melamine. alone and containing 5% of urea, based on the dry weight of the cotton. The untreated and treated pieces were tested for tensile strength and for shrinkage after three successive l-hour launderings, using the procedure described in Example 1. The results are shown in the following table.

Spun rayon cloth, 68 x 38 plain weave, was impregnated in finishing baths containing 12.5% of methylated methylol melamine, 0.38% ammonium hydrogen phosphate curing accelerator and 0.3% of a 25% solution of sodium dioctyl sulfosuccinate, a wetting agent. The wet pickup Tsar:

8 02. women's wear'all-wool flannel Tensile Strength Percent shrinkage after Wash No. Percent Percent Percent Resin Urea Thlourea Warp Fill 1 2 3 4 6 +1 hr.

Lbs. Lbs.

None None None 44. 7 341 5 11. 6 16. 7 18. 7 20. 8 23. 4 30. 0 10 None None 43.8 31. 8 2.3 2.2 3.4 3.6 4.6 4.4 10 1 45. 2 32. 6 2. 0 2. 6 2. 7 3. 4 3. 8 4. 2 10 1 47.1 33.6 2.2 2.6 3.0 3.0 3.4 3.6 10 3 44.3 36.5 2.6 3.2 3.4 3.0 4.6 4.2 10 3 48. 7 37. 8 2. 4 3. 4 6.0 4. 2 3.8 6.0 10 6 63.6 40.6 2.2 3.6 3.6 6.1 4.7 6.2

was 123% and the impregnated cloth contained 15.4% of methylated methylol melamine.

Urea in an amount sufficient to apply 3% to the cloth was added to the second bath. The iming tendencies of woolen textile material which comprises impregnating the woolen textile material with 2-15% of its-weight of curable methylated methylol melamine together with 1-10% of its weight of a member of the group consisting pregnated cloth was framed, dried at 180 F. and

cured minutes at 300 F. followed by a light of urea, thiourea and mixtures thereof and theresoaping in 0.1% sodium lauryl sulfate at 100 F. after subjecting the impregnated woolen textile for 10 minutes, rinsed and framed dry. material to an elevated temperature suflicient The tensile strength of the treated fabric was to cure the methylated methylol melamine to a measured and they were then tested for shrink- 1 substantially water-insoluble condition. age by the method described in Example 1. The 5. Resin-impregnated textiles resistant to results are expressed in the following table as pershrinking having a tensile strength not substancent shrinkage. tially less than the strength of the corresponding east. 1 2 3 4 5 (1) Untreated 55.3xo3 150x20 15.01120 15.0x2.0 15.0x2.0 15.01120 (2) +%resin 34.8)(606 x10 2.3x0.8 2.5x0 x0 25x0 (3)(2)+3%urea 54.6x62 45x10 5.0x0 5.0x0.3 5.01:0.3 5.0x1.0

What we claim is: untreated textiles, said textiles being impreg- 1. A method of controlling the shrinkage of nated with 2-15% of a cured alkylated methylol textiles which comprises impregnating the texmelamine together with 1-10% of a member of tiles with an aqueous dispersion of a curable the group consisting of urea, thiourea and mixalkylated methylol melamine and with from 1% tures thereof. 1 to 10%, based on the dry weight of the textiles, 6. Resin-impregnated textiles resistant to of a formaldehyde-binding substance selected shrinking having a tensile strength not substanfrom the group consisting of urea, thioure and tially less than the strength of the corresponding mixtures thereof and then heating the impreguntreated textiles. s textiies being impre nated textiles to dry them and cure the alkylated nated with 2 of a cured methy a d methmethylol melamine to a water-insoluble condiylol melamine together with 1-10% of a memtion. ber of the group consisting of urea, thiourea and 2. A method of controlling the shrinkage of mixtures thereof. textiles which comprises impregnating the tex- Res np oo e textiles resisttiles with an aqueous dispersion of a curable ant to shrinking having a te Strength o methylated methylol melamine and with from substantially less than the strength of the corre- 1% to 10%, based on the dry weight of the texsponding untreated woolen textiles, said textiles tiles, of a formaldehyde-binding substance seng mp d With 215% of a cured methlected from the group consisting of urea, thiourea 4o y d methylol melamine er with 0% and mixtures thereof and then heating the imof amember of e ro p consisting of ur a. pregnated textiles to dry them and cure the thiourea and mixtures thereofmethylated methylol melamine to a. water-insoluble condition. JOHN EDWARD LYNN.

3. A process of reducing the felting and shrink- LINTON FLUCK. ing tendencies of woolen textile material which comprises impregnating the woolen textile ma- REFERENCES CITED term h 4 f i s Weigh of cura l l yl- The following references are of record in the iattsed nlieliirylgl melamgre together with 1-10% of file of this patent:

we g o a mem r of the grou consistin of urea, thiourea and mixtures thereo? and there UNITED STATES PATENTS after subjecting the impregnated woolen textile Number Name Date material to a el vated temperature suflicient 2,174,534 Shipp Oct, 3, 1939 to r h lleviated ethylol melamine to a 2,311,489 Toland Feb. 16, 1943 s al y water-insoluble condition. 2,339,203 Stiegler Jan, 11, 1944 4. A process of reducing the felting and shrink- Re. 22,566

Johnstone Nov. 21, 1944 

